Proof-reading service
http://www.proof-reading-service.com/en/
Scientific writing must be accurate and informative, clear and consistent, and it also needs to follow strict formatting and stylistic guidelines. Proofreading Service provides editing services for researchers and scientists across all scientific fields, including medical, biological and physical sciences.

Writing.co.uk
http://www.writing.co.uk/
Writing.co.uk offer an editing fee based on the number of words involved, with a minimum fee of £50. Their proofreading services include checking and correcting grammar, spelling, capitalisation, forms of address, use of italics and other details. Writing.co.uk also offer suggestions to the author.